In a media statement, Subway New Zealand said any discrepancies in length are due to differences in the baking of its bread, which happens at each Subway location.

"We are committed to providing a consistent product delivering the same amount of bread to the customer with every order. The length however may vary slightly when not baked to our exact specifications," it said.

"We are reinforcing our policies and procedures in an effort to ensure our offerings are always consistent no matter which Subway restaurant you visit."

While Subway New Zealand had no problems with complaints over its foot-long, it told 3 News that occasional speculation over the size of the six-inch meant that staff kept a ruler under the counter to settle disputes.